如何在python中减去3小时的日期时间?

时间:2018-10-30 13:13:36

标签: python pandas numpy dataframe data-science

我在gmt中有两列日期时间,我需要减去此日期时间的三小时。例如在第4行中,我需要在3小时内减去startdate,结果是:08/02/2018 17:20:0。在同一行4a中,我需要在3小时内减去结束日期,结果是:08/02/2018 21:50:0。

初始表格

cpf  day  startdate              enddate
1234  1   08/01/2018 12:50:0     08/01/2018 15:30:0
1234  1   08/01/2018 14:30:0     08/01/2018 15:40:0
1234  1   08/01/2018 14:50:0     08/01/2018 15:50:0
1234  2   08/02/2018 20:20:0     08/03/2018 00:50:0
1234  3   08/03/2018 01:00:0     08/03/2018 03:50:0
1235  1   08/01/2018 11:50:0     08/01/2018 15:20:0
5212  1   08/01/2018 14:50:0     08/01/2018 15:20:0

结果表

cpf  day  startdate              enddate
1234  1   08/01/2018 09:50:0     08/01/2018 10:30:0
1234  1   08/01/2018 11:30:0     08/01/2018 10:40:0
1234  1   08/01/2018 11:50:0     08/01/2018 10:50:0
1234  2   08/02/2018 17:20:0     08/02/2018 21:50:0
1234  3   08/02/2018 22:00:0     08/03/2018 00:50:0
1235  1   08/01/2018 08:50:0     08/01/2018 10:20:0
5212  1   08/01/2018 11:50:0     08/01/2018 10:20:0

如何在python中做到这一点?

P.S .:请注意结果。谢谢!

3 个答案:

答案 0 :(得分:3)

您可以使用timedelta

from datetime import timedelta

df['startdate'] = pd.to_datetime(df['startdate']) - timedelta(hours=3)
df['enddate'] = pd.to_datetime(df['enddate']) - timedelta(hours=3)

答案 1 :(得分:3)

我相信您需要转换列to_datetime并减去3小时timedelta:

cols = ['startdate','enddate']
td = pd.Timedelta(3, unit='h')
df[cols] = df[cols].apply(lambda x: pd.to_datetime(x, format='%d/%m/%Y %H:%M:%S') - td

如果要分别为每个列提供适当的解决方案:

td = pd.Timedelta(3, unit='h')
df['startdate'] = pd.to_datetime(df['startdate'], format='%d/%m/%Y %H:%M:%S') - td
df['enddate'] = pd.to_datetime(df['enddate'], format='%d/%m/%Y %H:%M:%S') - td

print (df)
    cpf  day           startdate             enddate
0  1234    1 2018-01-08 09:50:00 2018-01-08 12:30:00
1  1234    1 2018-01-08 11:30:00 2018-01-08 12:40:00
2  1234    1 2018-01-08 11:50:00 2018-01-08 12:50:00
3  1234    2 2018-02-08 17:20:00 2018-03-07 21:50:00
4  1234    3 2018-03-07 22:00:00 2018-03-08 00:50:00
5  1235    1 2018-01-08 08:50:00 2018-01-08 12:20:00
6  5212    1 2018-01-08 11:50:00 2018-01-08 12:20:00

最后一次需要将日期时间转换为自定义格式:

df['startdate'] = df['startdate'].dt.strftime('%d/%m/%Y %H:%M:%S')
df['enddate'] = df['enddate'].dt.strftime('%d/%m/%Y %H:%M:%S')
print (df)
    cpf  day            startdate              enddate
0  1234    1  08/01/2018 09:50:00  08/01/2018 12:30:00
1  1234    1  08/01/2018 11:30:00  08/01/2018 12:40:00
2  1234    1  08/01/2018 11:50:00  08/01/2018 12:50:00
3  1234    2  08/02/2018 17:20:00  07/03/2018 21:50:00
4  1234    3  07/03/2018 22:00:00  08/03/2018 00:50:00
5  1235    1  08/01/2018 08:50:00  08/01/2018 12:20:00
6  5212    1  08/01/2018 11:50:00  08/01/2018 12:20:00

答案 2 :(得分:0)

您可以使用timedelta

示例代码

from datetime import timedelta 
delta = timedelta(hours=-3)